From the October 2006 issue

How we lost Pluto

Follow Astronomy's coverage of Pluto, politics, and the planet paradigm.
By | Published: October 21, 2006 | Last updated on May 18, 2023
Pluto
August 25, 2006
Astronomy magazine podcast: Pluto’s demotion
The world’s astronomers have removed Pluto’s planetary status.
Jeremy McGovern
Listen to the recording.

August 24, 2006; updated August 25
It’s official: IAU demotes Pluto
The world’s astronomers have removed Pluto’s planetary status.
Francis Reddy
Read more.

August 19, 2006
Scientists debate Pluto’s fate
Planetary scientists discussing a proposed definition for “planet” warmed to an alternative that would leave Pluto out in the cold.
Francis Reddy
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August 16, 2006
Pluto is a planet, but one of 12?
Astronomers consider embracing Pluto’s moon, the largest asteroid, and an icy body nicknamed Xena as planets in their own right.
Francis Reddy
Read more.

June 27, 2006
Pluto’s moon’s named
Hydra and Nix are the names of Pluto’s two small moons discovered last year.
Laura Baird
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April 26, 2006
Does Pluto have rings
Planetary scientist Alan Stern fills us in on the possibility.
Read more.

February 3, 2006
Planet debate heats up
Astronomers have verified the “tenth planet” is bigger than Pluto.
Matthew Quandt
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December 21, 2005
To Pluto and beyond
The New Horizons mission aims to get a good look at the solar system’s most distant reaches.
Laura Layton
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October 31, 2005
New moon for Pluto?
The Hubble Space Telescope may have observed two new moons orbiting Pluto.
Jeremy McGovern
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October 3, 2005
The “tenth planet” gets a sidekick
Astronomers find a satellite orbiting 2003 UB313.
Francis Reddy
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August 1, 2005
How close does Pluto’s orbit come to Neptune
Looking at a solar system diagram on paper, it appears the Pluto and Neptune orbits intersect. Of course, this is not the case.
Larry Wasserman
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July 30,2005; updated August 5
Tenth planet discovered
Move over, Pluto. There’s an even larger ice world in the outer solar system.
Francis Reddy
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July 21, 2005
Pluto’s moon revals atmosphere?
A recent multi-telescope observation of Charon passing in front of a distant star will help astronomers’ understanding of Pluto’s moon.
Matthew Quandt
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February 18, 2005
Pluto at 75
Nearly a century after its discovery, understanding Pluto still doesn’t come easy.
Steele Wotkyns
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Feburary 1, 2005
Day of discovery
On February 18, 1930, a Kansas farm boy discovered what was then the largest body found in the solar system in 84 years.
Kevin Schindler
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